#23144: merge with 3.4.

1 files changed, 23 insertions, 6 deletions

diff --git a/Lib/importlib/__init__.py b/Lib/importlib/__init__.py
index 1bc99474f2..b6a9f82e05 100644
--- a/Lib/importlib/__init__.py
+++ b/Lib/importlib/__init__.py
@@ -30,9 +30,26 @@ else:
         pass
     sys.modules['importlib._bootstrap'] = _bootstrap
 
+try:
+    import _frozen_importlib_external as _bootstrap_external
+except ImportError:
+    from . import _bootstrap_external
+    _bootstrap_external._setup(_bootstrap)
+    _bootstrap._bootstrap_external = _bootstrap_external
+else:
+    _bootstrap_external.__name__ = 'importlib._bootstrap_external'
+    _bootstrap_external.__package__ = 'importlib'
+    try:
+        _bootstrap_external.__file__ = __file__.replace('__init__.py', '_bootstrap_external.py')
+    except NameError:
+        # __file__ is not guaranteed to be defined, e.g. if this code gets
+        # frozen by a tool like cx_Freeze.
+        pass
+    sys.modules['importlib._bootstrap_external'] = _bootstrap_external
+
 # To simplify imports in test code
-_w_long = _bootstrap._w_long
-_r_long = _bootstrap._r_long
+_w_long = _bootstrap_external._w_long
+_r_long = _bootstrap_external._r_long
 
 # Fully bootstrapped at this point, import whatever you like, circular
 # dependencies and startup overhead minimisation permitting :)
@@ -73,7 +90,7 @@ def find_loader(name, path=None):
     except KeyError:
         pass
     except AttributeError:
-        raise ValueError('{}.__loader__ is not set'.format(name))
+        raise ValueError('{}.__loader__ is not set'.format(name)) from None
 
     spec = _bootstrap._find_spec(name, path)
     # We won't worry about malformed specs (missing attributes).
@@ -138,15 +155,15 @@ def reload(module):
                 parent = sys.modules[parent_name]
             except KeyError:
                 msg = "parent {!r} not in sys.modules"
-                raise ImportError(msg.format(parent_name), name=parent_name)
+                raise ImportError(msg.format(parent_name),
+                                  name=parent_name) from None
             else:
                 pkgpath = parent.__path__
         else:
             pkgpath = None
         target = module
         spec = module.__spec__ = _bootstrap._find_spec(name, pkgpath, target)
-        methods = _bootstrap._SpecMethods(spec)
-        methods.exec(module)
+        _bootstrap._exec(spec, module)
         # The module may have replaced itself in sys.modules!
         return sys.modules[name]
     finally: